# -*- coding: utf-8 -*- 
# @project : 《Atcoder》
# @Author : created by bensonrachel on 2021/7/14
# @File : （step2）A. Packing Rectangles（CF）.py
# https://codeforces.com/edu/course/2/lesson/6/2/practice/contest/283932/problem/A
# 二分思想，只要两边性质不一样都可以用二分的方法
w,h,n = map(int,input().split())
l = 0
r = max(w,h)* n + 1
while(l + 1 < r):
    mid = (l + r)//2
    if (mid//w) * (mid//h) >= n:
        r = mid
    else:
        l = mid
print(r)